[Discuss] Cold Boot Attacks on Encryption Keys

[tmetro+blu at gmail.com (Tom Metro)]

Richard Pieri wrote:
> Tom Metro wrote:
>> The scenario is that you have strongly encrypted data on disk,
>> decryption keys in memory, an OS configured so that it doesn't do
>> something stupid, like write the keys to unencrypted swap space, and an
>> OS hardened enough that physical access to the machine seems like the
>> easier attack vector.
> 
> The problem with this scenario is that it makes no sense. If your threat
> is physical attack then why aren't you hardening your physical intrusion
> prevention?

Oh, physical security is already excellent in this scenario. Locked
cage, 24/7 CCTV, and a security guard. The weakness is that your server
is in a data center owned by a 3rd party, who can simply hand the keys
over to someone else. The data center is legally obligated to comply
with any requests from law enforcement, and in many cases not required
or prohibited from informing you, so you have no opportunity to fight a
frivolous warrant or prevent your server from being swept up along with
a batch of your neighbor's servers.

This scenario has played out in the news a bunch of times in the past
few years. Figuring out how to secure data held in data centers, despite
physical access to the machines, is going to be one of the challenges of
the next few years.


> ...there's a simple...way for me to circumvent all of your
> clever...self-destructs... I go after your backups.

They're encrypted too, with keys only held in memory.

Of course having all these servers with keys only held in memory is
going to make some IT guy have a bad day when recovering from a power
failure. Not easy to scale this up to hundreds of servers while still
keeping things secure.

 -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/